Internal grinding fixture support



H. C. WEIMAR INTERNAL GRINDING FIXTURE SUPPORT Filed Dec.

May 29, 1951 Patented May 29, 1951 2,554,651 INTERNAL GRINDING FIXTURE SUPPORT Hans C. Weimar, Providence, R. -I., assignor to Brown and Sharpe Manufacturing Company, Providence, R. 1., a corporation of Rhode Island Application December 30, 1948, Serial No. 68,309

Claims. (Cl. 51-166) The present invention relates to improvements 'in' machine tools, and more particularly to an improved support for an internal grinding fixture adapted 'for use in a cylindrical grinding machine.

The invention is herein disclosed as embodied in a cylindrical grinding machine of the general type which comprises a longitudinally movable work support and a transversely movable grinding wheel spindle support mounted on a common base. Work is supported for external cylindrical grinding between headstock and footstock anvils on the work support and alternatively may be supported from the headstock alone for conventional internal grinding operations. The grinding equipment of the machine consists of a transversely extending wheel spindle and grinding'wheel mounted thereon for external grinding which are rotatably supported on fixed bearings on the grinding wheel spindle support, and an alternatively available internal grinding fix.- ture including an internal grinding bracket and an interal grinding wheel spindle rotatably supported thereon which is adapted to be positioned in substantial alignment with the work. In the illustrated construction the internal grinding fixture referred to is pivotally supported to be moved about the same axis of rotation with the external grinding wheel-spindle between a lowered operative position in which the internal grinding wheel spindle is located" in substantial alignment with thework, and the raised inoperative position shown. Y

It is a principal object of the present invention to provide in a grinding machine of the general typeabove described an improved support for the internal grinding fixture referred to, which is simple andat the same time efficient in construction and operation and iswell adapted, in combination with the associated'parts of the internal grinding fixture, to provide an effective support for the internal grinding wheel spindle in each of its operative and inoperative'positions.

,It is a further object of the invention to provide an adjustable support adapted for use with a grinding wheel fixture includin a pivotally supported internal grinding bracket, which is well adapted to be set up with a minimum of effort and to provide a rigid support of maximum strength for the internal grinding wheel fixture in its operating position. In carrying out the invention, a hinged abutting member or prop is provided which is pivotally mounted on the grinding wheel supportsubstantially beneath the pivotal support for the internal grinding bracket and engages against either of two alternative abutments on the internal grinding bracket for supporting the bracket in each of its inoperative and operative positions, and a clamping bolt which is connected between the hinged abutting member and the grinding wheel support in such a manner as to pull together and rigidly secure the internal grinding bracket and hinged abutting member in locking position with relation to the grinding wheel support. 7.

With the above and other'objects in view, as may hereinafter be noted, the several features of the invention consist also of the devices, combinations, and arrangement of parts hereinafter described and claimed, which, together with the advantages to be obtained thereby, will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawing, in which Fig. 1 is a view in right side elevation of a grinding machine, with portions thereof broken away and sectioned to show particularly the internal grinding fixture and hinged support therefor, which forms particularly the subject matter of the invention; these parts being shown in full lines for the operative position thereof, and in dot-and-dash lines to indicate the inoperative position thereof.

Fig. 2 is a detail view in front elevation taken on a line 2-2 of Fig. 1, illustrating particularly the internal grinding fixture and associated support in the raised inoperative position shown in dot-and-dash lines in Fig. 1; and

Fig. 3 is an enlarged detail view" in front elevation, partly in section, taken on a line 3-3 of Fig. 1, illustrating the internal grinding fixture and associated support in the full line position of Fig. 1. v

The several features of the invention are particularly illustrated as embodied in the grinding wheel assembly of a cylindrical grinding machine, in which the work is supported on centers on a work support for rotational movement and in which the work support and grinding wheel support are adapted for relative feeding and positioning movements longitudinally and transversely of the work axis. Only so much of the machine is disclosed as is believed necessary to illustrate the connection of the present invention thereto. 5

Referring more specifically to the drawing, the grinding wheel assembly shown comprises a large grinding wheel I'D for external grinding mounted on a grinding wheel spindle l2 supported to turn on a horizontal axis on a grinding wheel spindle support [4. The machine is further prov1ded with an internal grinding fixture which takes the form of a bracket IS on which are carried a support 98 and an internal grinding wheel spindle 26. The bracket 16 is formed with two rearwardly extending arms which are pivotally supported on a bushing 22 which surrounds the grinding wheel spindle I2 so that the internal grinding fixture may be readily swung upwardly from the operative position shown in full lines in Fig. 1, to the raised inoperative position shown in dot-and-dash lines in that figure.

The drive for each of the external and internal grinding wheel spindles above described is provided by an electric motor mounted on a rearward extension of the grinding wheel spindle support Hi. As indicated in Fig. l of the drawing, the drive for the internal grinding wheel spindle 2B is taken from the armature shaft of the motor, indicated at "2 by means of a belt 26 which passes around a pulley 28 on the armature shaft 24 and around a pulley 33 on the internal grinding wheel spindle 20.

In accordance with the present invention the internal grinding bracket i6 is adapted to be supported in each of its inoperative and operative positions by means of a hinged abutting member 34 in the form of a plate formed at its lower end with two bearing lugs journaled to receive a pivot pin 36 mounted on a fixed portion of the grinding wheel support M. A tension spring 38, connected at one end to the hinged abutting member 34 and at its other end to an eye on the grinding wheel support, acts to bias the abutting member 34 upwardly against the under side of the internal grinding bracket. For the lowered operative position of the internal grinding bracket I shown in full lines in Fig, 1 and in Fig. 3, the abutting member 34 is engaged against an abutment provided by a pair of stop screws 39 adjustably supported in depending lugs 40 formed on the rearwardly extending arms of the internal grinding bracket l6. 7

The position of the abutting member 34 upwardl against the under side of the internal grinding bracket i6 is accurately determined by the engagement of the upper edge of the member 34 against a finished bearing surface 42 formed on a centrally disposed depending lug M on the bracket l6.

Further in accordance with the invention a tightening bolt it is adapted for the operative position of the internal grinding bracket {5 to be inserted rearwardly through a hole in the centrally located lug 44 into a screw-threaded socket 48 formed on the grinding wheel support l4 above the level of the pivot 36 and below the level of the grinding wheel spindle !2. When the bolt 46 is now tightened, the internal grinding bracket IE will be forced downwardly against the abutting member 34, and at the same time the bracket and hinged abutting member will be forced rearwardly on their respective pivots to provide an extremely rigid unyielding assembly of the internal grinding fixture in its operative position.

When it is desired to return the internal grinding fixture to its inoperative position, the bolt 46 is withdrawn to an inoperative position where it is held by a spring clip 49 and the bracket I6 is then swung upwardly to the inoperative position shown in dot-and-dash lines in Fig. 1. During this movement of the bracket 58 the hinged abutting member 34, biased by its spring 38, rides against the under sides of the'bracket arms until it drops behind abutment pin 50 mounted on one of the arms, as shown in Fig. 2, to latch the internal grinding fixture firmly in its raised inoperative position.

The novel support for the internal grinding fixture illustrated and described, comprising the hinged abutting member 34 with the tightening bolt 45, has the important advantage that it provides a simple and eiiective supporting structure of great strength and rigidity for the internal grinding wheel spindle when in its operating position, while the abutting member 34 is available also to provide a firm support for the internal grinding fixture in its raised inoperative position. The hinged construction of the abutting member 34 employed in accordance with the invention has the further advantage that, for the raised inoperative position of the internal grinding bracket 34, the abutment or support on which the internal grinding fixture is mounted also swings out of the way and is wholly removed from any position inwhich interference might arise with the work or the footstock during traversing movement of the work support in the performance of an external grinding operation.

The invention having been described, what is claimed is:

1. In a grinding machine having a grinding wheel support, a grinding wheel spindle for cylindrical grinding on said support and an internal grinding fixture including an internal grinding bracket pivotally supported coaxially with said spindle on the support for movement between alternate lowered operative and raised inoperative positions, the combination of a hinged abutting member having a supporting pivot on the grinding wheel support beneath said grinding wheel spindle, means acting yieldably against the hinged abutting member to bias the hinged abutting member against the bracket, abutments on said bracket cooperating with said hinged member to support the bracket in each of said operative and inoperative positions, and a tightening device connected between said bracket and support for the operative position of the bracket to draw the bracket against the hinged member.

2. In a grinding machine having a grinding wheel support, and an internal grinding fixture comprising an internal grinding spindle, and a supporting bracket on which the internal grinding spindle is carried pivotally mounted on said grinding wheel support for movement between alternative operativeand inoperative positions, the combination of a supporting device for the bracket comprising a hinged abutting member having a supporting pivot on the grinding wheel support beneath the bracket, an abutment on the bracket against which the abutting member engages in the operating position of the fixture, and a tightening bolt connected between the bracket and support to draw the bracket abutment against the hinged member.

3. In a grinding machine having a grinding wheel support, a grinding wheel spindle for cylindrical grinding mounted on said support and an internal grinding fixture including an internal grinding bracket pivotally supported coaxially with said spindle on the support for movement between alternate lowered operative and raised inoperative positions, the combination of a hinged abutting member having a supporting pivot on the grinding wheel support beneath said grinding wheel spindle, an abutment on the under side of the bracket against which the abutting member engages at a supporting angle relative to the bracket in the operative position, and a tightening device connected between said abutment and a portion of the support located between the grinding wheel spindle, and said support acting to draw the bracket against its pivotal support and against the hinged member.

4. In a grinding machine having a grinding wheel support, a grinding wheel spindle for cylindrical grinding mounted on said support and an internal grinding fixture including an internal grinding bracket pivotally supported coaxially with said spindle on the support for movement between alternate lowered operative and raised inoperative positions, the combination of a hinged abutting member having a supporting pivot on the grinding wheel support beneath said grinding wheel spindle, an abutment comprising a pair of stop elements, each adjustably supported from the bracket, and spaced laterally from one another against which the abutting member engages at a supporting angle relative to the bracket in its lowered operative position, said bracket having the bottom surface thereof shaped for controlling the upward position of the hinged abutting member in said operative position, and an abutment on the bracket behind which the hinged member engages for the raised inoperative position of the internal grinding bracket.

5. In a grinding machine having a grinding wheel support, a grinding wheel spindle for cylindrical grinding mounted on said support and 6 an internal grinding fixture including an internal grinding bracket pivotally supported coaxially with said spindle on the support for movement between alternate low operative and raised inoperative positions, the combination of a hinged ,abutting member having a supporting pivot on the grinding wheel support beneath said grinding Wheel spindle, an abutment comprising a pair of adjustable stop screws threaded to the bracket and spaced laterally from one another against which the abutting member engages at a supporting angle relative to the bracket in its low operative position, means acting yieldably against the hinged abutting member to bias the hinged member against the bracket, a tightening device connected between a portion of said bracket disposed between said stop screws and a portion of the support disposed between said spindle and the pivot of said hinged member acting to draw the bracket against its pivotal support and against the hinged member.

HANS C. WEIMAR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 582,097 Roos May 4, 1897 2,063,659 Booth Dec. 8, 1936 

